A. Precedents Cited and Their Influence
i. Sufficiency review and the elements of conspiracy
United States v. Alaniz, 726 F.3d 586, 600 (5th Cir. 2013), supplied the rule that preserved sufficiency challenges receive de novo review. That independent review, however, does not permit appellate judges to retry the facts. Under United States v. Scott, 159 F.3d 916, 920 (5th Cir. 1998), the question is whether any rational factfinder could establish the offense beyond a reasonable doubt when the evidence and reasonable inferences are viewed favorably to the verdict.
United States v. Freeman, 56 F.4th 1024, 1025 (5th Cir. 2023), confirmed that this standard applies equally to direct and circumstantial evidence. That principle was particularly important because the government established agreement and knowledge through coordinated conduct and communications rather than direct evidence identifying every participant in the trafficking operation.
United States v. Isgar, 739 F.3d 829, 835 (5th Cir. 2014), quoting United States v. Moreno-Gonzalez, 662 F.3d 369, 372 (5th Cir. 2011), characterized review as highly deferential to the verdict. Similarly, United States v. Grant, 683 F.3d 639, 642 (5th Cir. 2012), quoting United States v. Loe, 262 F.3d 427, 432 (5th Cir. 2001), reserved the weighing of conflicting evidence and witness credibility to the jury. These authorities prevented the defendants’ alternative, innocent interpretations from becoming a basis for appellate reweighing.
United States v. Vargas-Ocampo, 747 F.3d 299, 303 (5th Cir. 2014) (en banc), supplied the three essential elements: an agreement to violate narcotics laws, the defendant’s knowledge of that agreement, and voluntary participation. The court measured the government’s proof against those elements—not against an additional requirement to identify the drugs’ supplier, installer, packager, or ultimate recipient.
ii. Expert testimony, preservation, and prejudice
United States v. Vargas, 580 F.3d 274, 278 (5th Cir. 2009), required plain-error review because neither defendant objected to Captain Jeff Davis’s testimony at trial. This made the absence of a demonstrated prejudicial effect especially consequential.
The court also relied on United States v. Cuellar, 478 F.3d 282, 293–94 (5th Cir. 2007) (en banc), for the importance of explaining how omitted disclosure would have supplied additional grounds for cross-examination. Neither defendant provided that explanation. The opinion expressly acknowledged that this decision was reversed on other grounds in Regalado Cuellar v. United States, 553 U.S. 550 (2008). The reference concerns the lower decision’s procedural history, not an independent substantive basis for affirmance here.
iii. Juror impartiality and trial-court discretion
United States v. Dejean, 988 F.3d 813, 816 (5th Cir. 2021), quoting United States v. Hinojosa, 958 F.2d 624, 631 (5th Cir. 1992), established the district court’s broad discretion to evaluate prospective jurors’ impartiality. These cases supported a restrained appellate approach to the removal of Juror 31.
United States v. Wharton, 320 F.3d 526, 535 (5th Cir. 2003), quoting Soria v. Johnson, 207 F.3d 232, 242 (5th Cir. 2000), supplied the substantive test: whether a prospective juror’s views would prevent or substantially impair performance of the juror’s duties under the instructions and oath.
Mu'Min v. Virginia, 500 U.S. 415, 424 (1991), quoting Rosales-Lopez v. United States, 451 U.S. 182, 188 (1981), explained why such determinations resist review from a written transcript. Trial judges observe demeanor and assess credibility directly. This rationale allowed the district court to give greater weight to Juror 31’s admitted bias than to his subsequent, qualified statement that he believed he could follow instructions.
iv. The Confrontation Clause and co-conspirator statements
United States v. Acosta, 475 F.3d 677, 680 (5th Cir. 2007), established plain-error review of Nero’s unpreserved confrontation challenge.
Crawford v. Washington, 541 U.S. 36, 53–54 (2004), supplied the central constitutional rule: testimonial statements by an absent witness ordinarily cannot be admitted unless the witness is unavailable and the defendant previously had an opportunity for cross-examination. The court discussed that rule through United States v. King, 93 F.4th 845, 851 (5th Cir. 2024).
United States v. King, quoting United States v. Duron-Caldera, 737 F.3d 988, 992–93 (5th Cir. 2013), also supplied the relevant definition of “testimonial”: a statement whose primary purpose is establishing or proving past events potentially relevant to a later prosecution. The opinion noted the denial of certiorari under the name Diggs v. United States, 145 S. Ct. 213 (2024). That denial adds no separate merits reasoning.
The decisive application came from United States v. Holmes, 406 F.3d 337, 348 (5th Cir. 2005): statements made during and in furtherance of a conspiracy are generally nontestimonial. United States v. Jackson, 636 F.3d 687, 694 (5th Cir. 2011), reinforced that proposition. United States v. Gurrola, 898 F.3d 524, 535 n.17 (5th Cir. 2018), described the nontestimonial character of co-conspirator statements as settled circuit law. Together, these authorities supported treating Brown’s explanations as operational efforts to preserve the drug shipment rather than testimony created for prosecution.
v. Minor-participant sentencing reductions
United States v. Martinez-Larraga, 517 F.3d 258, 272 (5th Cir. 2008), supplied plain-error review because Brown had not raised the requested adjustment below.
United States v. Martinez, 921 F.3d 452, 483 (5th Cir. 2019), identified the relevant considerations: knowledge of the activity’s scope, participation in planning, decision-making authority, the nature and extent of participation, and anticipated benefit. These factors required an assessment of Brown’s actual involvement rather than reliance on the label “courier.”
United States v. Gallegos, 868 F.2d 711, 713 (5th Cir. 1989), made that distinction explicit: a courier is not necessarily substantially less culpable than the average participant. It directly undermined any assumption that physically transporting drugs automatically warrants mitigation.
B. Legal Reasoning
i. The evidence established a coordinated undertaking, not merely association
The court evaluated the evidence cumulatively. Nero arranged the vehicle and its location; Brown flew to collect it; their communications reflected coordinated decisions; and their earlier travel and checkpoint discussions supplied context for the charged trip. Brown’s false account, reaction to the screwdriver, and continued telephone contact with Nero during the stop strengthened the inference of knowing participation.
The concealed drugs did not, by themselves, resolve knowledge. Instead, their quantity and value operated alongside the defendants’ conduct and communications. The court therefore did not adopt a rule that a driver necessarily knows about drugs hidden inside a vehicle.
The defendants argued that their messages reflected a romantic relationship rather than a criminal partnership. The court answered that those relationships were not mutually exclusive. More importantly, selecting among reasonable competing interpretations belonged to the jury.
The government also did not have to reconstruct the entire distribution network. Its obligation was to prove these defendants’ agreement, knowledge, and participation. Missing evidence about upstream suppliers or downstream recipients did not defeat otherwise sufficient proof of those elements.
ii. Expert disclosure depended on a request, while relevance depended on a factual connection
The disclosure analysis began with Federal Rule of Criminal Procedure 16(a)(1)(G)(i). As quoted by the court, the government’s written expert-disclosure obligation arises at the defendant’s request. Neither defendant made that request. The government nevertheless notified them that it intended to present fentanyl-distribution expertise and later identified Davis.
The opinion’s qualification matters: the voluntary disclosure tracked the rule’s pre-2022 language and might not have supplied everything required by the amended provision. The court nevertheless found no effect on substantial rights. Thus, the decision should not be read as approving an outdated disclosure form whenever a proper request triggers the current rule.
Davis’s testimony also had concrete relevance. His explanation of fentanyl pills and pill presses illuminated the defendants’ messages about pills and suppliers. His quantity testimony supported an intent to distribute, while valuation supported an inference of knowing participation in a valuable enterprise. The reasoning concerned a common distribution method; it does not establish that fentanyl can only be distributed in pill form.
iii. A juror’s promise to follow instructions did not conclusively eliminate admitted bias
Juror 31 expressly acknowledged a predisposition favoring the defense. His later statement that he believed he could follow instructions did not compel the district court to accept him as impartial.
The court assessed the entire exchange and the trial judge’s opportunity to observe tone, demeanor, and body language. This was a contextual credibility judgment, not a categorical rule that any initial expression of concern makes a juror unfit. The Sixth Amendment protects an impartial jury, not retention of a particular prospective juror who expresses sympathy for one side.
iv. The roadside statements advanced an unfinished conspiracy
The confrontation analysis turned on both timing and function. Brown spoke before officers deployed the dog and discovered the drugs. At that stage, successful deception could still have allowed her to continue transporting the shipment.
Her explanations about the rental, travel, and screwdriver sought to present an innocent account and avoid detection. The court accordingly regarded them as statements furthering the conspiracy’s objectives, rather than statements primarily intended to establish facts for prosecution.
This is the opinion’s most distinctive application of existing doctrine: statements directed to police can remain nontestimonial when their operative purpose is to facilitate an ongoing conspiracy through deception. Their police audience did not alone determine their constitutional character.
The holding has limits. It does not classify every statement by a conspirator as nontestimonial, nor does it decide how to treat a formal accusation or confession made after the conspiracy’s objectives have ended. The court relied on the particular statements’ role in attempting to preserve the ongoing transportation scheme.
v. Brown’s participation exceeded the assumptions associated with a minor courier
Brown’s adjustment claim failed because the record reflected sustained involvement. She transported a highly valuable shipment, communicated about planning and decisions, and had a history of similar travel and operational discussions.
Nero’s apparent supervisory role did not necessarily make Brown a minor participant. The inquiry was not simply whether someone else exercised more authority, but whether Brown’s own involvement justified the requested reduction under the governing factors.
Because Brown did not request the adjustment below, the appellate question was whether the district court plainly erred by failing to apply it on its own initiative. Her extensive involvement supplied a sufficient basis to reject that claim. The opinion does not establish that couriers are categorically ineligible for minor-role treatment.